DOT/FAA/AR-97/2, II Proceedings of the Office of Aviation Research FAA-NASA Symposium on the Continued Washington, D.C. 20591 Airworthiness of Aircraft Structures FAA Center of Excellence in Computational Modeling of Aircraft Structures Atlanta, Georgia August 28-30, 1997 July 1997 This document is available to the U.S. public through the National Technical Information Service, Springfield, Virginia 22161 NOTICE This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The United States Government assumes no liability for the contents or use thereof. The United States Government does not endorse products or manufacturers. Trade or manufacturer's names appear herein solely because they are considered essential to the objective of this report. Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient's Catalog No. DOT/FAA/AR-97/2, II 4. Title and Subtitle 5. Report Date PROCEEDINGS OF THE July 1997 FAA-NASA SYMPOSIUM ON THE CONTINUED AIRWORTHINESS OF AIRCRAFT STRUCTURES 6. Performing Organization Code 7. Author(s) 8. Performing Organization Report No. Compiled by Catherine A. Bigelow, Ph.D. 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) Federal Aviation Administration NASA Langley Research Center Airport and Aircraft Safety Materials Division Research and Development Division Hampton, VA 23681 11. Contract or Grant No. William J. Hughes Technical Center Atlantic City International Airport, NJ 08405 12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered U.S. Department of Transportation Proceedings Federal Aviation Administration August 28-30, 1996 Office of Aviation Research Washington, DC 20591 14. Sponsoring Agency Code AAR-400 15. Supplementary Notes Edited by Catherine A. Bigelow, Ph.D, Federal Aviation Administration, William J. Hughes Technical Center 16. Abstract This publication contains the fifty-two technical papers presented at the FAA-NASA Symposium on the Continued Airworthiness of Aircraft Structures. The symposium, hosted by the FAA Center of Excellence for Computational Modeling of Aircraft Structures at Georgia Institute of Technology, was held to disseminate information on recent developments in advanced technologies to extend the life of high-time aircraft and design longer-life aircraft. Affiliations of the participants included 33% from government agencies and laboratories, 19% from academia, and 48% from industry; in all 240 people were in attendance. Technical papers were selected for presentation at the symposium, after a review of extended abstracts received by the Organizing Committee from a general call for papers. 17. Key Words 18. Distribution Statement Corrosion, Crack detection, Nondestructive inspection, Document is available to the public through the National Residual strength, Fatigue, Crack growth Technical Information Service, Springfield, Virginia 22161 19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price Unclassified Unclassified 346 Form DOT F1700.7 (8-72) Reproduction of completed page authorized CONTENTS Volume I Executive Summary................................................................................................................vii Airframe Life Extension Through Quantitative Rework Inspections, W. H. Sproat................1 Analysis of a Composite Repair, C. Duong and J. Yu............................................................17 Analysis of Safety Performance Thresholds for Air Carriers by Using Control Charting Techniques, A. Y. Cheng, J. T. Luxh•j, and R. Y. Liu......................................25 Analytical Approaches and Personal Computer (PC)-Based Design Package for Bonded Composite Patch Repair, Y. Xiong, D. Raizenne, and D. Simpson..................................37 Analytical Fatigue Life Estimation of Full-Scale Fuselage Panel, J. Zhang, J. H. Park, and S. N. Atluri................................................................................................51 Analytical Methodology for Predicting the Onset of Widespread Fatigue Damage in Fuselage Structure, C. E. Harris, J. C. Newman, Jr., R. S. Piascik, and J. H. Starnes, Jr..........................................................................................................................63 Application of Acoustic Emission to Health Monitoring of Helicopter Mechanical Systems, A. F. Almeida, W. D. Martin, and D. J. Pointer................................................89 Applying United States Air Force Lessons Learned to Other Aircraft, G. D. Herring, R. D. Giese, and P. Toivonen....................................................................93 Automated Evaluation of Residual Strength in the Presence of Widespread Fatigue Damage, W. T. Chow, H. Kawai, L. Wang, and S. N. Atluri.........................................101 Controlling Fatigue Failures by Means of a Trade-Off Between Design and Inspection Parameters, A. Brot........................................................................................109 Controlling Human Error in Maintenance: Development and Research Activities, W. B. Johnson and W. T. Shepherd................................................................................117 Coordinated Metallographic, Chemical, and Electrochemical Analyses of Fuselage Lap Splice Corrosion, M. E. Inman, R. G. Kelly, S. A. Willard, and R. S. Piascik........129 Designing for the Durability of Bonded Structures, W. S. Johnson and L. M. Butkus.........147 The Effect of Crack Interaction on Ductile Fracture, C. T. Sun and X. M. Su.....................161 The Effect of Environmental Conditions and Load Frequency on the Crack Initiation Life and Crack Growth in Aluminum Structure, H.-J. Schmidt and B. Brandecker.......171 iii Effects of Combined Loads on the Nonlinear Response and Residual Strength of Damaged Stiffened Shells, J. H. Starnes, Jr., C. A. Rose, and C. C. Rankin..................183 Elasto-Plastic Models for Interaction Between a Major Crack and Multiple Small Cracks, K. F. Nilsson......................................................................................................197 An Energetic Characterization of the Propagation of Curved Cracks in Thin Ductile Plates, H. Okada and S. N. Atluri....................................................................................225 Engineering Fracture Parameters for Bulging Cracks in Pressurized Unstiffened Curved Panels, J. G. Bakuckas, Jr., P. V. Nguyen, and C. A. Bigelow..........................239 Evaluation of Closure-Based Crack Growth Model, C. Hsu, K. K. Chan, and J. Yu...........253 Failure Analysis of Aircraft Engine Containment Structures, S. Sarkar and S. N. Atluri......................................................................................................................267 Fatigue and Damage Tolerance of Aging Aircraft Structures, G. I. Nesterenko...................279 Fatigue Growth of Small Corner Cracks in Aluminum 6061-T651, R. L. Carlson, D. L. Steadman, D. S. Dancila, and G. A. Kardomateas.................................................301 Fatigue Studies Related to Certification of Composite Crack Patching for Primary Metallic Aircraft Structure, A. Baker..............................................................................313 Volume II Executive Summary................................................................................................................vii Fatigue-Life Prediction Methodology Using Small-Crack Theory and a Crack-Closure Model, J. C. Newman, Jr., E. P. Phillips, and M. H. Swain............................................331 Full-Scale Glare Fuselage Panel Tests, R. W. A. Vercammen and H. H. Ottens.................357 A Graphic User Interface (GUI) Front-End for Parametric Survey and its Application to Composite Patch Repairs of Metallic Structure, H. Kawai, H. Okada, and S. N. Atluri......................................................................................................................369 Implementation and Application of a Large-Rotation Finite Element Formulation in NASA Code ZIP2DL, X. Deng and J. C. Newman, Jr....................................................377 Implications of Corrosion Pillowing on the Structural Integrity of Fuselage Lap Joints, N. C. Bellinger and J. P. Komorowski.........................................................391 Improved Nondestructive Inspection Techniques for Aircraft Inspection, D. Hagemaier and D. Wilson..........................................................................................403 iv Improving the Damage Tolerance of Bonded Structures Via Adhesive Layer Barriers, J. C. Brewer......................................................................................................417 In Search of the Holy Grail—The Deterministic Prediction of Damage, D. D. Macdonald and J. Magalhaes.................................................................................425 Investigation of Fuselage Structure Subject to Widespread Fatigue Damage, M. L. Gruber, K. E. Wilkins, and R. E. Worden.............................................................439 Numerical Investigations into Viability of Crack Tip Opening Displacement as a Fracture Parameter for Mixed-Mode I/II Tearing of Thin Aluminum Sheets, M. A. Sutton, W. Zhao, X. Deng, D. S. Dawicke, and J. C. Newman, Jr.......................461 A Numerical Study of the Interactions Between Multiple Longitudinal Cracks in a Fuselage (Multiple